Power knockout device for machine tools



7 y 1941- s. N. LEVESQUE rA 2,240,506

POWER KNOCKOUT DEVICE FOR MACHINE TOOLS Filed March 14. 1940 2Sheets-Sheet 2 atented May 6, 194 1 S PATENT OFFICE POWER KNOCKDUTDEVICE FOR MACHINE TOOLS George N. Levesque and Merrill F. Sebring,Providence, R. I., assignors to Brown and Sharpe Manufacturing Company,a corporation of Rhode Island Application March 14, 1940, Serial No.323,930

8 Claims.

The present invention relates to improvements n machine tools, and moreparticularly to an imvroved power knockout device adapted to disonnectone or a plurality of interrelated mov- .ble supports from poweroperation.

The invention is herein disclosed as embodied n a plane grinding machineof the general type iaving a horizontally disposed and verticallyadustable grinding wiheel spindle, and a work supiorting assemblyincluding a stationary base sup- )Ol't, a saddle support transverselymovable on he base, and a work supporting table longitudiially movableon the saddle support. The illusrated machine is provided with poweroperating neans including a'starting, stopping and rerersing clutch,connections therefrom for drivng the table, and additional connectionswhich nay be rendered operative with each reciproca- ;ion of the tableto impart a stepped cross feeding novement to-the saddle support. Aclutch shiftng mechanism is provided which may be of ordiriarydescription for controlling the operation of the work table, and isarranged to be controlled either manually from a feed lever, orautomatizally bytable dogs. A booster device associated with the clutchshifting mechanism acts to shift the clutch to its alternate engagingposition at each reversal of the table drive in order to provide for acontinuous automatic reciprocation of the table under the control of thetable dogs.

It is a principal object of the present invention to provide a novel andimproved knockout device which may be actuated manually or automaticallyif so desired, by means of stop dogs on the saddle support to d sconnectthe power drive vfor the work supporting assembly.

Applicants improved knockout device in the preferred form hereinafterillustrated and described, comprises a spring actuated device forshifting the table clutch to neutral position, a spring-pressed detentnormally operative to lock the clutch shifting device out of operation,a knockout element operable through the agency of cooperating camsurfaces to withdraw the de-' tent, and manual and dog-actuatedcontrollers plan view taken on the line 2-2 of Fig. 1; Fig. 3

is a detail sectional view, taken on the line 3-3 of Fig. 2; Fig. 4 is asectional view taken on the line 4-4 of Fig. 1; Fig. 5 is an enlargeddetail view in right side elevation of the knockout eleboth rigidlyconnected to and forming an integral unit with the knockout element.

With the above stated and other objects in view as may hereinafterappear, the several features of the invention consist in the devices,combina-.

tions and arrangement of parts hereinafter described and claimed, whichtogether with the advantages to be obtained thereby will be readilyunderstood from the following description taken in connection with theaccompanying drawings,

ment, with a portion of the same broken away to illustrate the ball andcam actuating connection;

Fig. 6 is an enlarged detail sectional view taken on the line 6-6 ofFig. 2; Fig. '7 isa detail sectional view of the power knockout devicetaken on the line 1-1 of Fig. 5, the knockout device being shown in itslocked inoperative position; and Fig. 8 is a detail sectional view takenon the line 8-8 of Fig. 5.

The surface grinding machine shown in the drawings comprises generally abase 10, a saddle support I 2 supported for forward and back movement onways l4 on the base l0, and alongitudinally movable work supportingtable [8 supported in ways I 8 and 20 on the saddle support l2.

A column 22 provides support for a horizontally arranged and verticallyadjustable grinding wheel spindle (not shown) and a grinding wheel 24.

The illustrated machine is provided with power means for reciprocatingthe table l6 and for imparting step-by-stepcross feeding movements tothe saddle support l2. The power connections for driving the tablecomprise a horizontally arranged and forwardly extending drive shaft 26provided at its forward end with a bevel pinion 28 which meshes with anddrives in opposite directions two bevel gears 30 and 32 which are loose-1y sleeved on a cross shaft 34. A clutch member 38 interposed betweenthe driving gears and 32 and keyed to the shaft 34 is arranged to bemoved axially from an intermediate neutral positionintp clutchingengagement alternatively with either of the bevel drive gears 30, 32, todrive the shaft 34 alternatively in opposite directions. A bevel gear 38on the shaft 34 meshes with a bevel gear 40 on a forwardly extendingshaft 42 which also carries a gear 44 meshing with a gear 46 o n thetable feed shaft 48 suitably supported in bearings onthe base I 0. Thetable is driven from the feed shaft 48 through a train of gearssupported on the saddle support l2, best shown in Figs. 2 and 4 of thedrawings. These connections include a pinion 50 which is keyed to turnwith and to move axially on the shaft 48 and is supported between twodownwardly extending arms 52, 54, on the saddle support l2. The pinion50 meshes with a table feed gear which is supported between the arms 82and 64 and is arranged for meshing engagement with a rack 56 on theunder side 'of the work supporting table I6.

i For manual operation of the table. a hand wheel 51 is provided securedto the forward end of a hand wheel shaft 50 which is in axial alignmentwith the shaft 42 and carries at its rear end a gear 59 adapted forengagement with a gear 60 on the table feed shaft 48. The hand wheel 51and shaft 58 are movable axially between alternate operative andinoperative positions in which the gear 69 is brought into or out ofmeshing relation with the gear 60. A spring-pressed plunger 6I arrangedfor engagement alternatively with two annular grooves inthe shaft 58serves to lock the hand wheel in either of these positions.

The mechanism for effecting cross feeding movements of the saddlesupport I2 comprises a rearwardly extending cross feed shaft 62 (seeFigs. 1 and 4) which is supported against axial movement in a bearing 63in the machine base, and has formed integrally therewith a feed screw 64meshing with a nut 68 rigidly secured to the saddle support I2. Manualcross feeding movements may be imparted to the saddle support I2 bymeans of a cross feed hand wheel 68 secured to the forward end of thecross feed shaft 62.

The present machine is provided with a power cross feed mechanism whichis arranged to impart one stepped cross feeding movement to the saddlesupport I2 for each full reciprocation of the work table I6. Thismechanism is driven from the table feed shaft 48, and comprises a crossfeed rack (see Figs. 1, 3 and 4) which is actuated by each reversal ofthe drive of the table feed shaft 48, and acts through a pawl andratchet mechanism to impart successive incremental rotational movementsto the cross feed shaft 62 and feed screw 64. The rack 10 is pivotallysupported by means of a pin 12 on a pawl the front side of carryingsleeve member 14 (Figs. 2 and 3) loose on the table feed shaft 48. Adouble pawl member I6 secured to a supporting pin 18 is mounted on thesleeve member 14, and is arranged to be rocked to alternative engagingpositions with a driving ratchet 80 secured to the feed shaft 48. Theposition of the pawl is determined by means of a radially extendinglever arm 82 secured to the pawl pivot pin 18. The lever arm 82 is inturn controlled by a lever arm 84 connected by means of a frictiondevice 85 to turn with the table drive shaft 48. Rotation of the tabledrive shaft 48 acting through the friction arm 84 will rock the pawl 16in a corresponding direction to operatively engage the pawl with theratchet 80 to rotate the sleeve 14 and to correspondingly shift the rack10. This rocking movement continues until arrested by the engagement ofthe arm 82 and an'adjacent lug 88 on the sleeve member 14 with one oftwo adlustably positioned stop pins 90. Upcin reversal of the shaft 48,this operation will be repeated in a reverse direction to impart areturn movement to the rack 10. As best shown in Figs. 1 and 4, the rack10 is arranged for meshing engagement with a pinion 92 formed on asleeve member 93 supported to turn on the cross feed shaft 62.. Thesleeve member 93 is provided at its forward end with a bell-shapedextension 94. A pivot pin 96 secured to the under side of the bell 94provides support for a double pawl 98 which is arranged to mesh ineither of two alternative positions with a'ratchet I00 secured to thecross feed shaft 62. A spring-pressed plunger I02 seated on the may beeffected manually by means member 94 is arranged to engage with a camsurface 91 formedintegrally with the pawl 98. Engagement of the pawlwith the V-shaped central portion of the cam surface 91 acts to supportthe pawl in intermediate neutral position in which the power cross feedis disconnected.

Movement of the pawl in either direction from the central position iseffected by means of a downwardly extending manual -control arm I04 andcauses the plunger I02 to ride into engagement with either of twosloping cam surfaces arranged on opposite sides of the V-shaped notch tosupport one or the other tip portion of the pawl in engagement withtheratchet I00 for effecting a step-by-step power cross feed of the saddlesupport I6 alternatively in either direction.

Starting, stopping and reversal of the table drive and the power crossfeed associated therewith, is eifected by means of control mechanismwhich serves to control the position of the main clutch member 36. Theshifting of the clutch of table actuated dogs through connections whichinclude a rock shaft I08 mounted in bearings I09, I I 0, on the saddlesupport I2. A manual feed lever III is secured to the forward end of therockshaft I08. Also mounted on the rock shaft is an upwardly extendinglever arm 'I I2 which is arranged to be acted upon by reversing tabledogs H3, H4, adjustably supported in a T-shaped slot H5 in the worksupporting table I6.

Adjacent its rear end the shaft I08 is provided with a downwardlyextending fork II 1 which embraces a rod II8 carried on two upwardlyextending arms I20, I22 rigidly secured to a rock shaft I24 which alsoprovides support for the clutch shifting lever I 26. This lever takesthe form of a fork on the arms of which are supported two rollers I28for engagement in a clutch shifting groove I 30 in the clutch member 36.The clutch shifting lever I26 is secured in an adjusted angular positionto turn with the rock shaft I24 through connections which comprise alever arm I32 extending laterally from the sleeve hub of the clutchshifting lever I26. and having formed thereon a U-shaped portion toreceive two adjusting screws I34. These adjusting screws engage betweenthem a lug I36 formed on a lever arm I88 secured to the rock shaft I24.

The lever arm I38 forms part of a booster mechanism for automaticallyfully shifting the running position to reverse the table at the end ofits travel in each direction during machine operation. A roller I40carried on the forked outer end of the lever I 38 is arranged forengagement with a cam member I42 formed on the outer end of aspring-pressed plunger I44 which is slidably supported, but is keyedagainst rotational movement within an axial bore formed in a sleevesupport I46 rigidly mounted on the base I 0. A compression spring coiledabout a reduced portion of the sleeve support I46 and seated at one endagainst a shoulder I48 on the sleeve support, and at its other endagainst the member I42, tends to support the cam member I42 inengagement with the roller I40. The cam surface of the member I42 isV-shaped, the roller I40 for an intermediate position of the clutchmember 36 being arranged the point of the V, so that any additionalmovement of the clutch shifting lever beyond center under the influenceH3 or III! will render the corresponding sloping surface of the camoperative to shift the lever to ride upon of the table reversing dogs rmI38 and clutch 36 controlled thereby to its illy engaged position.

In accordance with the present invention, apiicants provide a.- noveland improved mechaism which may be controlled automatically by ogs onthe saddle support I2 or by a manually perable trip lever to shift thedriving clutch 5 to neutral position and thereby to stop the Iachine.The mechanism for shifting the iutch 36 to its neutral positioncomprises a rock aaft I54 which is rotatably supported intermeiate itslength in a bearing I56 formed in a fixed racket I58, and at its forwardend is fitted with manual control knob I60. The sleeve hub of me knobI60 is journalled in a bearing I62 seured in the front wall of the baseI0, providing dditional support for the rock shaft I54. A ross bar I64secured to the rear'end of the rock haft I54 has formed thereon two pinsI66 which re spaced on opposite sides of a rod I68 form- 12 an extensionof the lever arm I32 on the leeve hub of the clutch shifting lever I26.A orsion spring I coiled about the rock shaft 54 and attached at one endto the knob and at ;s other end to the bearing support I62 tends tocollar I93 pinned to the end of the plunger I80 supports the bushing I90against axial slipp ge on the plunger. At its inner end the sleevemember I88 is fitted with a ball and a cam con-.

nection which is rendered operative by rotational movement of the sleevemember I88 to, force the sleeve member and plunger I80 axiallyoutwardly. The ball and cam connection referred to, comprises two pairsof conical-shaped cam recesses I94, I96 oppositely located in the outerface of the bushing I82 and in the recessed abutting face of the sleevemember I88. Two steel 7 balls I98 are fitted into the recesses I94, I96.

ock the shaft I54 in a counterclockwise direcion to the position shownin Fig. 2, in which 0th pins I66 are engaged with and support the 0dI68, and clutch shifting lever I26 associated herewith in anintermediate neutral position as hown in Fig. 2.

In order to start the table in power operatio he operator first rotatesthe knob I60 and shaft 54 through 90 in a clockwise direction, thusmoving the pins I66 relatively away from the 0d I68, so that the clutch36 is free to move to either of its driving positions. The rock shaft 54is then locked in this running position by he engagement of a detent I14with a recessed :houlder I16 formed in the periphery. of an ecaentricdisk I18 secured to the rock shaft I54. the detent I14 is formed on theend of a plunger ran slidably supported in a journal bearing I8I n thebase I0 and in a flanged bushing I82 rigidy held in place by screws I83.The plunger I80 s supported against rotational movement by neans of akey I84 which is fitted into keyways formed in the plunger I80 andbushing I82. A :ompression spring I86 coiled about the plunger I80 andseated at one end against the bearing I82 and at its other end againstthe enlarged dead of the plunger forming-the detent I14, serves tosupport the detent yieldingly in engagement with the peripheral surfaceof the eccentric iisk I18.

In accordance with a principal feature of the present invention,applicants provide a novel and improved knockout device for disengagingthe main clutch 36 which may be operated automatically by stop dogscarried on the saddle support I2, or alternatively by means of amanually operable knockout lever. This mechanism Is arranged to retractthe plunger I80 and detent I14, thereby releasing the rock shaft I54which then rotates in a counterclockwise direction under the influenceof its spring I10, causiim the clutch member 36 to be shifted to neutralposition by the engagement of pins I66 with the rod I68.

The knockout mechanism specifically comprises a knockout element in theform of a sleeve member I88 which is supported to turn on a bushing I90on the plunger I80, and is seated at its outer end against an end thrustbearing formed by a flange I92 on the bushing I90. A

The inward pressure exerted on the plunger I80 and sleeve member I88 bythe spring I86 tends normally to maintain the sleeve member I88 in anangular position in which the balls I98 are seated in the bottoms of theconical-shaped cam recesses I94, I96, and in which the detent I18 ispermitted to engage in a locking position against the recessed shoulderI16. With this arrangement of the parts, it will readily be seen thatrotational movement of the knockout element or sleeve member I88 ineither direction, will cause the sleeve member I88 to be forcedoutwardly by the operation of the ball and cam connection abovedescribed, carrying with it the plunger I80 and detent I14 to disengagethe detent from the notched recess I16, and thereby to disengage theclutch 36. It will be seen also that with the recessed construction ofthe sleeve member I88 above referred to, a protecting flange is providedwhich at all times covers and provides adequate protection for the balland cam connection against possible entry of dirt or grit.

Further in accordance with the present invention, a particularly simpleand efllcient construction and arrangement of the knockout device isprovided in which the knockout element or sleeve member I88 is arrangedto be controlled either manually or automatically by means of manual anddog-actuated controllers which are formed as integral parts of theknockout element. A forwardly extending control lever 200formedintegrally with the sleeve member I88 provides convenient meansunder the control of p on the sleeve member I88, an upwardly extendingarm 202 which is arranged to be engaged by either of two stop dogs 204,206 adjustably supported in a T-shaped [slot 208 in the right hand endof the saddle support I2. The continued step-by-step cross feed of thesaddle support I2 during power operation of the machine, will cause oneor the other of the stop dogs 204, 206 to engage with and rock the leverarm 202 and sleeve member I88, thereby disengaging the detent I14 fromits notched recess I16 to throw out the clutch member 36 and stop themachine It will be understood that the invention is not limited to thespecific embodiment shown, and

that various deviations maybe made therefrom without departing from thespirit and scope of the appended claims.

What is claimedis:

1. In a machine tool having a support assembly comprising a plurality ofsupports movable in diverse directions, and power means forreciprocating one of said supports and for moving another of saidsupports in a diverse direction, a power throw-out device includingactuating means having a yielding action to disconnect said supportsfrom power operation, a detent normally operative to lock said powerthrow-out device out of operation, a knockout element having manuallyactuated and dog actuated controllers attached integrally therewith,dogs on said diversely movable supportfor engagement with said dogactuated controller, and cam means rendered operative by actuation ofsaidknockout element to wi hdraw the detent.

2. In a machine tool having a support assembly comprising a plurality ofsupports movable in diverse directions, and power means forreciprocating one of said supports and for moving another of saidsupports in a diverse direction, a power throw-out device includingactuating means having a yielding action to disconnect said supportsfrom power operation, a detent plunger normally operative to lock saidpower throw-out device out of operation, a knockout element sleeved onsaid detent plunger and having manually actuated and dog actuatedcontrollers attached integrally therewith, dogs on said diverselymovable support for engagement with said dog-actuated controller, andcam means rendered operative by rotational movement of said knockoutelement to withdraw the detent plunger.

3. In a machine tool having a support assembly a manual controller and adog-actuated controller attached thereto, and dogs rendered operative bymovement of said diversely movable sup-- port to engage with saiddog-actuated controller.

comprising a plurality of supports movable in diverse directions, powermeans including a clutch having neutral and alternate reverse runningpositions, and connections therefrom for reciprocating one of saidsupports, and means actuated by said connections for moving another ofsaid supports in a diverse direction, clutch shifting means controlledby movement of said first-mentioned support for automaticallyreciprocating the same, a yieldingly acting device for shifting theclutch to neutral position, a detent normally operative to lock saidclutch shifting device out of operation, a knockout element, and cammeans rendered operative by movement of the knockout element to withdrawthe detent and thereby to permit action of said device to shift heclutch to neutral position.

4. In a machine tool having a support assembly comprising a plurality ofsupports movable in diverse directions, power means including :a clutchhaving neutral and alternate reverse running positions, and connectionstherefrom for reciprocating one of said supports and for moving anotherof said supports in a diverse direction, clutch shifting means operableto control the movement of said supports, a yieldingly acting device forshifting the clutch to neutral position, a detent plunger, meanssupporting said detent plunger yieldingly in position to lock saiddevice out of operation, a knockout element supported torotate withrelation to and to move axially with said detent plunger, and cam meansrendered operative by rotational movement of said knockout element towithdraw said knockout element and detent plunger therewith axially topermit action of said device to shift the clutch to neutral position;

5. In a machine tool having a support assembly comprising a plurality ofsupports movable in diverse directions, power means including a clutchhaving neutral and alternate reverse running positions, and connectionstherefrom for reciprocating one of said supports, and for moving anotherof said supports in a diverse direction, clutch shifting means operable.to control the movement of said supports, a'yieldingly acting devicefor shifting the clutch to neutral position, I

a detent normally operative to lock said clutch shifting device out ofoperation, a knockout element actuable to withdraw the detent and having6. In a machine tool having a support assembly comprising a basesupport, and a saddle support and a main support movable in diversedirections on said base support, power means including a clutch on saidbase support having neutral and reverse running positions, connectionstherefrom for moving the main support and for moving said saddlesupport, clutch shifting means operable to control the movement of saidmain support and saddle support, a clutch throwout device includingmeans having a yielding action to shift the clutch to neutral position,a detent plunger, and spring means for supporting said plunger normallyin position to lock said device out of operation, a knockout elementcomprising a sleeve member rotatable on the plunger, and cam meansrendered operative by rotational movement of the knockout element towithdraw the detent plunger and thereby to permit action of saidthrowout device to shift the clutch to neutral position, said cam meansbeing further arranged to be acted upon by said plunger supportingspring means to return the plunger and knockout element to their initialposition.

7. In a machine tool having a support assembly comprising a-basesupport, and a saddle support and a main support movable in diversedirections on said base support, power means including a clutch on saidbase support having neutral and reverse running positions, connectionstherefrom for moving the main support, and for moving the saddlesupport, clutch shifting means operable to control the movement of saidmain support and saddle support, a clutch throw-out device including arock shaft and means tending to rock said shaft in a direction to shiftthe clutch to neutral position, an eccentric disk having a recessed stopsurface mounted. on the shaft, a detent plunger slidably andnonrotatably mounted on the base support for engagement with said stopsurface to lock said device out of operation, spring means urging theplunger against the eccentric disk, a knockout element comprising asleeve member rotatable on the plunger and connected to move the plungeraxially therewith, and a ball and cam connection interposed between thebase support and the sleeve rendered operative by rotational movement ofthe sleeve member for imparting an axial movement thereto to withdrawthe detent plunger and thereby to permit rotational movement of the rockshaft to shift the clutch to neutral position.

8. In a machine tool having a support assembly comprising a basesupport, and a saddle support and a main support movable in diversedirections on said base support, power means including a clutch on saidbase support having neutral and reverse running positions, connec; tionstherefrom for moving the main support, means actuated by saidconnections for moving said saddle support, clutch shifting meanscontrolled by movement of said main support for automaticallyreciprocating the same, a clutch throw-out device including means havinga yielding action to shift the clutch to neutral position, a detentplunger slidably and non-rotatably mounted on the base support, andspring means for urging said plunger axially into position to lock saiddevice out of operation, a knockout element comprising a sleeve memberrotatably supported on the detent plunger and connected to move thedetent plunger axlally therewith, 'a ball and cam connection interposedbetween a. recessed face of the sleeve member and an abutting surface ofthe base support, whereby rotational movement of the sleeve member iseflectlve to impart an axial withdraw movement to the sleeve member endplunger associated therewith, a

- manual controller and a. dog actuated controller formed integrallywith said sleeve member, and dogs on the saddle support for engagementwith 5 said dog-actuated controller.

GEORGE n. LEvEs UE; F. smo.

